> RTTY was based upon the frequency > of Mark (2125) and Space (2295) and the surplus military > equipment available, unless you could afford some of the high > dollar HAL equipment (which was also used by the military).
No, RTTY is always "Shift low" - that is Mark is the HIGHER RF frequency and space is the LOWER RF frequency. When the audio tones 2215 and 2295 are applied to a LSB transmitter in AFSK this results in the correct shift. > I have no idea what the protocol is for DATA (perhaps Elecraft > can tell us.) As an experiment, try switching rigs in MixW and > observe what is happening to the signal frequency. FSK D and AFSK A receive in LSB while PSK D and DATA A receive in USB for compatibility with the (backward) convention of most non- RTTY software writers (PSK32, MFSK, etc.). 73, ... Joe, W4TV > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Rich (KE0X) > Sent: Friday, June 27, 2008 4:49 PM > To: elecraft@mailman.qth.net > Subject: Re: [Elecraft] K3 Firmware 2.10,1.81 problems Update > > > > As Julian suggested the problem is in MixW. It has been 40 > years since I had the RTTY training course in the NAVY, but, > it has to do with the convoluted history of RTTY. Although > SSB is on the LSB on the HF bands below 30 Meters and USB on > those bands above 30 meters (Many reasons given for this most > of which are not correct) RTTY was based upon the frequency > of Mark (2125) and Space (2295) and the surplus military > equipment available, unless you could afford some of the high > dollar HAL equipment (which was also used by the military). > Military protocol was to have the Mark the lowest tone in > frequency. This was ok with most equipment made BPC (Before > Personnel Computers). The PC brought out the conversion of > telephone modems, use of the modem IC’s and finally the PC > sound card for generating these tones. If you built a TNC out > of a modem chip and did not include a reverse switch you were > stuck to either the low or high bands. This was fixed on the > PC with a button to reverse the signal that you could click > on and copying. Some of the Rigs treat RTTY as SSB, others > put RTTY so that the Mark is always the lowest frequency > transmitted regardless of the band selected, and RTTYR > reverses this. I have no idea what the protocol is for DATA > (perhaps Elecraft can tell us.) As an experiment, try > switching rigs in MixW and observe what is happening to the > signal frequency. You wil not be able to chang frequency > with MixW but you can see what happens to the signal as you > turn the dial on the RIG. > > Rich, > KE0X > > > -- > View this message in context: > http://www.nabble.com/K3-Firmware-2.10%2C1.81-problems-Update- tp18154703p18163577.html Sent from the Elecraft mailing list archive at Nabble.com. _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
